<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
  <link rel="stylesheet" href="style.css">
    <script src="lodash.js"></script>

</head>

<body>
    <div id="app">
        <button @click="add">随机插入一个数字</button>
        <button @click="remove">随机移除一个数字</button>
        <button @click="shuffle" >洗牌</button>
         <transition-group name="list">
             <span v-for="item in items" :key="item" class="list-item">
                 {{item}}
             </span>
         </transition-group>
    </div>
    <script>
        var vm = new Vue({
            el:"#app",
            data:{
                items:[1,2,3,4,5,6,7],
                nextNum:8
            },
            methods:{
                randomIndex(){
                    return Math.floor(Math.random()*this.items.length)
                },
                add(){
                    this.items.splice(this.randomIndex(),0,this.nextNum++)
                },
                remove(){
                   this.items.splice(this.randomIndex(),1) 
                },
                shuffle(){
                    this.items = _.shuffle(this.items);
                }
            }
        })
    </script>
</body>
</html>